Editor’s Note: Reporting for this story was supported by the Pulitzer Center on Crisis Reporting.

This story is a collaboration between the Puente News Collaborative, a bilingual, nonprofit newsroom and funder dedicated to high-quality, fact-based news and information from the U.S.-Mexico border, and Public Health Watch, a nonprofit investigative newsroom based in Texas.

By Mariana Hernandez

By the time Evelyn Morales learned that her brother, Alberto, had been diagnosed with kidney failure in the United States, she knew the disease well. One of her sisters had died of the same condition four years earlier.

Alberto worked on construction crews and painted houses across the U.S. for more than a decade. But one day, the 37-year-old’s body gave out. Struck by fever and pain, he could no longer work.

“My mother told him to come back to El Salvador,” Evelyn said in an interview in her home, which borders a sugar cane plantation in Jiquilisco. “She told his wife to find a way to buy his ticket, because if he died, she wanted to bury him in his homeland.”

Mesoamerican nephropathy, a form of chronic kidney disease, represents a growing health crisis among Central Americans, at home and in the U.S.

The illness, whose exact cause remains unknown, appears to have a common origin: It strikes people mostly along the Pacific coast of Central America, from Costa Rica to Guatemala. Experts studying the disease point to a combination of likely causes, including exposure to agrochemicals, heat stress from prolonged hard labor in hot weather, and inadequate hydration.

Ramon García Trabanino, vice president of the Latin American Society of Nephrology and Arterial Hypertension, who has studied the disease since the 1980s, said the illness follows the heat. With climate change, the region is only getting hotter.

“The illness is here to stay. Global warming and heat will continue complicating things,” he said. “There’s no hope; every year it will get worse.”

A young migrant’s disease

In El Salvador’s eastern Usulutan department, one of the areas most affected by the disease, young laborers – some of them minors – put in long hours in farm fields under the sun or in construction. Young police officers on the beat and monitoring traffic also face heat stress.

Without proper health care, kidney damage can start in adolescence. Yet the symptoms take time to appear, usually after repeated heat stress has damaged the kidneys. Because migration from the region has been significant in recent decades, symptoms often appear when young workers who once toiled under a Central American sun show up in clinics and emergency rooms – in the U.S.

If they get sick in the U.S., they can seek expensive treatment, or return to countries where public clinics are saturated and private medical care is accessible to the wealthy and those who receive remittances from relatives living and working abroad.

Hard work, tragic consequences

At age 14, siblings Alberto and Evelyn began working side by side in the sugar cane fields that dominate the landscape around the town of Jiquilisco, some 70 miles southwest of San Salvador. Under a blazing sun, they worked long shifts, often skipping water breaks to finish faster. In 2016, Alberto decided to migrate to the United States, just as thousands  of  Salvadorans  had  since  the 1980s. When he left, his

community was caught in the middle of a gang turf war.

Alberto jumped into arduous jobs in the U.S., but it wasn’t long before his body began showing signs of trouble: He often ran unexplained fevers, and his muscles constantly ached.

Nonetheless, he labored on, finally stopping in 2024, when he could no longer stand.

“In the U.S., you can’t afford to get sick, because if you don’t pay rent, they’ll put you out on the street,” Evelyn said.

After an examination, a doctor delivered the grim news. “He said (Alberto’s) kidneys were no longer working,” Evelyn said.

That year, Alberto faced the difficult choice: stay in the U.S., where health care was beyond his means, or return home to seek a spot at a government-supported hospital.

“These are workers that are doing the jobs that no one else wants to do (in the U.S.), and they have limited or no access to health care,” said Roxana Chicas, associate professor at the School of Nursing at

Emory University in Atlanta. “And they get sick, and there’s no mechanism in place to take care of this workforce.”

Chicas said that many of those who fall ill do not remain in the U.S. to receive treatment. “Probably around half go back to their home countries in search of affordable care,” she said, noting that the number is difficult to pin down because there’s no good system in the U.S. to track undocumented migrants with renal dysfunction.

U.S. research on non-traditional causes of renal failure aims to identify gaps in care for agricultural workers and construction crews. Chicas believes it will add insights into how rising temperatures affect laborers.

A multinational crisis

According to university and hospital reports in the U.S., Mesoamerican nephropathy disproportionately affects migrants between 22 and 45 years old, mostly men who’ve emigrated from high-risk areas, from southern Mexico to El Salvador and Nicaragua. The two Central American countries have reported the highest number of deaths linked to the disease. The latest reliable numbers, from a 2019 report by the Pan American Health Organization, show 67.4 deaths per 100,000 population in El Salvador. Globally, the region ranks among the highest in renal failure rates and the lowest in treatment rates.

Government health data from El Salvador estimates that chronic kidney disease from non-traditional causes affects about 3.8% of the population, rising to 6% among men. Official mortality rates for all forms of chronic kidney disease increased from 45 deaths per 100,000 population to 60 per 100,000 in 2022. The Health Ministry says about half of those deaths occurred in the Bajo Lempa region. Nationwide,

more than 7,300 patients are registered in public dialysis programs.

Doctors working in affected communities say the official numbers underestimate the scale of the disease. They point to local studies dating back to 2014 that found much higher rates of kidney failure and death, registering an annual average incidence rate of 1,410 cases per million people, two-thirds of whom did not report diabetes or hypertension – the usual precursors to kidney trouble. Salvadoran clinicians said government figures mainly include patients who make it into the public health system, while many others die at home or never receive treatment because of the cost or a lack of access to medical care.

Dr. Raúl Guevara, who works at the CURE Consortium, an international initiative focused on finding causes of chronic kidney disease of uncertain origin, said that when researchers began recruiting study participants in El Salvador, they sought people who had participated in earlier studies and had elevated creatinine levels, a leading early indicator of the disease. But when they arrived in communities to follow up with study subjects, they were told the individuals were gone; they’d migrated north.

“Because of the economic hardship people face here, the disease ends up reaching other countries’ medical systems, like those of the United States and Mexico,” Guevara said.

The study into the risk factors of renal disease, which will last at least 10 years, is being conducted with experts in the affected countries and at U.S. universities.

“These pathologies belong to other hemispheres, other latitudes,” said Emmanuel Jarquin, one of the study’s lead researchers. “But our population migrates (to other countries), and the disease arrives in their health systems.”

The study’s goal is to prevent the disease, a silent killer detectable only by regular testing. But by the time symptoms appear, kidney damage is irreversible and requires dialysis or transplants.

Survival With a Price Tag

For Salvadoran migrants who show symptoms in the U.S. and seek treatment, options are limited. Without health insurance, treatment in the U.S. is out of reach for many migrants. Those who go back to El Salvador face a tough reality; treatment at home for chronic kidney disease is also a struggle. Public healthcare systems are overwhelmed, and private treatment costs remain beyond their reach.

In rural El Salvador, Pablo Rivera faced the limits of treatment after he learned his kidneys were failing. At age 37, he was told he needed renal replacement therapy. He said he felt like his world had collapsed. He had seen his father and his favorite childhood teacher in El Salvador die from the same disease.

Filled with fear and under pressure from his wife, he began seeking treatment openings in the Salvadoran public health system, but found none. In the U.S., his brother-in-law began sending money to pay for private treatment at a nearby clinic. (In 2025, remittances from migrants in the U.S. totaled $9.9 billion – a cash flow the Salvadoran Central Bank says has steadily grown over the years.)

For two years, remittances from Rivera’s brother-in-law covered one of the two private clinic treatments that ran up to $120 each. When he could no longer work, his wife and eldest daughter took jobs in cornfields and sold home-made cakes, joining the many women caring for kidney patients who’ve had to take on extra work.

In El Salvador, a single dialysis treatment costs around $120, while in the U.S., the price can reach $500 without insurance. But the minimum wage in El Salvador is about $409 a month for industrial and

service jobs, and just $273 in agriculture, the sector employing most people affected by kidney disease.

What’s worse is the shortage of hospital beds, mainly in parts of El Salvador where the disease is most prevalent. In Usulutan, the small town near Rivera’s home, only one public hospital offers dialysis. To reach others, patients must travel two hours to San Miguel, the nearest big city, or almost four hours to the capital, San Salvador.

The weight of the treatment became too heavy for Rivera’s family. After two years of remittances, his brother-in-law could no longer send money.

“That day I told my wife I was going to die, because we didn’t have the economic means for me to live,” he said. “We put our hopes in God’s hands.”

An Overcrowded System

Renal replacement therapies, like dialysis, have overwhelmed hospitals in El Salvador, where there are only half the number of kidney disease specialists as the global average. Denis Calero, a doctor at the National Jiquilisco Hospital, said the country is faced with a double burden; apart from the young patients, there’s also chronic kidney failure in older adults with diabetes or hypertension.

“This is a disease that cannot be cured, but it can be prevented,” said Calero, who today treats about 1,000 patients whose renal troubles are “under control,” and more who are on deeper replacement therapy in the hospital and his private practice in the town of Jiquilisco.

For now, Rivera and Alberto are medically stable. Two days a week, they travel to the hospital in Usulután, where they finally found free public treatment after spaces became available.

But each visit seems to bring a new loss. Rivera says that almost every time he arrives for treatment, he notices another familiar face is missing. These are friends who lost their fights against the disease. Those moments make him mentally count the number of years and months they had lived with the disease, a habit he tries hard to push from his mind.

He keeps himself busy to avoid dwelling on his condition. In late afternoons, when the heat eases, Rivera still works his family’s corn plot. The routine is a distraction, he said.

“It’s very hard because I already have a wife and kids, and I love my family,” he said. “It’s hard to think that I’m going to leave them one day.”

Mariana Hernández Ampudia is a multimedia journalist based in Mexico City. Her reporting focuses on Latin America, environmental issues, immigration and Mexican politics.